When it comes to chain burgers, as trite as it sounds Red Robin is tough to beat. Personally, I go with the guacamole burger with bleu cheese instead of the swiss or whatever usually comes on it.
Guac, Bacon, Mayo and the usual garden [lettuce, onion, tomato]. Oh, and I substitute Ghost Pepper aoli for the mayo as well for a kick.
The Burning Love is pretty good too. And the grilled jalapeno on top is LEGIT hot
As a bonus, their fries with Campfire Sauce [mayo, BBQ sauce and chipotle powder] is WAAAAY better than potatoes have any right being.